GMail GTD = GTDGmail | 43 Folders:
"GTDGmail looks like a promising entry into the increasingly crowded gene pool of web-based productivity software.
The Firefox extension runs on top of your Gmail account, giving you an email-centric approach to implementing Getting Things Done that includes contexts, statuses, a very nifty search feature, and more. This could be just the thing for people who have to live in email, but who don’t want to live in an unprocessed inbox."
Note that this isn't available yet - hope their time management is good!!